.trans {
    /*transition*/
    -webkit-transition: 0.3s ease;
    -moz-transition: 0.3s ease;
    -ms-transition: 0.3s ease;
    -o-transition: 0.3s ease;
    transition: 0.3s ease;
}
.test_outer {
    background-color:lime;
    width: 320px;
    height: 480px;
    margin: 1em auto;
    position: relative;
    overflow:hidden;/* 因为遮罩层肯定比实际区域大，所以遮罩层的限制层：overflow：hidden控制不出现滚动条 */
}
.test_cover {
    /* 定义镂空区域宽高大小尺寸 */
    width: 60px;
    height: 60px;
    border: 580px solid rgba(0, 0, 0, .45);/* 使用元素的大border作为遮罩层的 */
    border-radius: 50%;
    position: absolute;
}

.test_cover_pos1 {
    left: -327px;
    top: -578px;
}
.test_cover_pos1:after {
    content: '☺首先选择您所在的城市';
    margin: 16px 0 0 -140px;
}

.test_cover_pos2 {
    left: -547px;
    top: -478px;
}
.test_cover_pos2:after {
    width: 140px;
    content: '☺全新推图订餐服务，给你不一样的体验！';
    margin: 16px 0 0 60px;
}

.test_cover_pos3 {
    left: -437px;
    top: -158px;
}
.test_cover_pos3:after {
    content: '☺随时拨打订餐！';
    margin: -20px 0 0 -20px;
    white-space: nowrap;
}

.test_cover_pos1:after, .test_cover_pos2:after, .test_cover_pos3:after {
    color: #fff;
    font-family: '微软雅黑';
    text-shadow: 1px 1px rgba(0,0,0,.35);
    position: absolute;
}